1. Field of the Invention
This invention relates to internal combustion engines.
More specifically, the present invention relates to means for preventing detonation in internal combustion engines.
In a further and more specific aspect, the instant invention concerns means for venting excess pressure from the combustion chamber of an internal combustion engine.
2. The Prior Art
Detonation is a phenomenon well known to those skilled in the art of internal combustion engines. During the compression cycle, as the piston moves upwardly within the cylinder, the fuel/air mixture is compressed within the combustion chamber. At a predetermined time, as controlled by the ignition system, the spark plug produces an electrical spark to ignite the compressed mixture, known as the charge. In a properly functioning engine, combustion of the charge proceeds as a flame-front progressing from the point of ignition. The gases of combustion, expanding at a controlled rate, drive the piston downwardly, commencing the power cycle.
During detonation, combustion of the charge is uncontrolled. As a result of excessive engine loading, improper fuel/air mixture, extreme ambient temperatures, and numerous other determinants, the charge burns at an accelerated rate. In extreme cases, simultaneous burning at the entire charge may occur in a literal explosion. Since the piston is unable to move in direct response to the uncontrolled combustion, and may be still traveling upwardly in the compression stroke, the burning charge and the gases being produced are subjected to compression rather than being allowed to expand.
A discernible pressure differential exists between controlled and uncontrolled combustion. Maximum combustion pressure, in a normally functioning internal combustion engine, is of a magnitude in the range of 800 to 900 pounds per square inch. Detonation generally occurs when the pressure within the combustion chamber achieves a magnitude in the range of 1100 to 1200 pounds per square inch. Accordingly, it is apparent that detonation is preceded by a rise in pressure.
In addition to producing an audible indication, colloquially known as "knock" or "ping", detonation can be extremely deleterious to the engine. In minor cases, detonation may result only in temporary loss of engine performance or damage to the spark plugs. Extreme or prolonged detonation is responsible for such major damage as broken connecting rods and burned pistons.
The occurrence of detonation has been recognized by the prior art for many years. Various purported solutions have been advanced. In general, attempts to suppress detonation involve providing secondary chambers or cavities. One configuration of secondary chamber was especially devised to provide a cushioning effect for the burning charges. The cavities in other designs are for the purpose of attenuating acoustic waves.
Such efforts by the prior art, however, have been generally unsuccessful. It is now known that detonation is preceded by an excessive increase in pressure. Under normal conditions, where the pressure increase in the combustion chamber is insufficient to produce detonation, an auxiliary chamber presents an escape for the expanding gases which are deterred from exerting force upon the piston. In cases of extreme detonation, the auxiliary chamber is insufficient to accommodate the excess pressure. It is also noted that providing an auxiliary chamber is exceedingly expensive and not compatible with conventional production-line manufacturing techniques.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object of the present invention to provide improved means for attending to detonation in an internal combustion engine.
Another object of the invention is the provision of means for the prevention of detonation.
And another object of this invention is to provide means for venting excess pressure from the combustion chamber of an internal combustion engine.
Still another object of the invention is the provision of detonation control means suitable for original equipment manufacture or retrofit to pre-existing internal combustion engines.
Yet another object of the instant invention, in accordance with one embodiment thereof, is to provide detonation prevention means which can be installed as an integral part of an internal combustion engine with minimal tools and skills.
Yet still another object of the invention is the provision of detonation prevention means which, in accordance with another embodiment thereof, can be incorporated into an internal combustion engine without modification to the engine.
And a further object of the invention is to provide detonation prevention means which is readily and conveniently adjustable to accommodate the operating characteristics of a particular engine.
Still a further object of the immediate invention is the provision of readily replaceable pressure relief means for an internal combustion engine.
Yet a further object of the invention is to provide detonation prevention means which is relatively maintenance free and extremely effective.
And yet a further object of the invention is the provision of means, according to the foregoing, which is relatively simple and inexpensive to manufacture.